It is planned to continue our research program during the coming 5 to 7 years in the same broad areas of investigation in which this project has been conducted over the preceding 13 years. The research will be aimed broadly, as in the past, at the neural basis of perception, learning and memory; the developmental patterning and regeneration of nerve connections, and aspects of cerebral organization and hemispheric specialization and interaction utilizing the split-brain approach. Seven years would carry the research to within but a few years of the Principal Investigator's retirement when it will be time to phase out and/or transfer the program. The projected research is focused around several somewhat distinct projects that involve different procedural approaches and different animal species: (a) studies of cerebral function in human patients with complete and partial sections of the forebrain commissures, hemispherectomy, agenesis of the corpus callosum, and related unilateral lesions, (b) studies on split-brain monkeys and cats with special emphasis on analytic experimental surgery in the visual system, (c) studies on nerve regeneration, development, and maturation in lower vertebrates and in neonate kittens with emphasis on neurospecificity and functional plasticity, (d) studies on memory consolidation and learning in newly hatched chicks. The current balance of emphasis on these different projects, as indicated below in the abstracts of research under investigation during this preceding year, may be expected to shift somewhat in response to personnel turnover and according to which particular experiments may develop the promising leads.